This week in Edwards history Published May 31, 2018 By 412th Test Wing Public Affairs EDWARDS AIR FORCE BASE, Calif. -- One June 1, 1951, Air Force aeromedical researcher Maj. John Stapp was strapped into a rocket sled that was poised on a 2,000 foot deceleration track at North Base. Moments later, 4,000 pounds of rocket thrust blasted him down the track and into the braking system (from 88.6 mph to a full stop in 18 feet). For a brief instant, he endured 48 g with a rate of onset of about 500 g per second. In other words, his body had absorbed an impact of more than four tons. Prior to Stapp’s sled experiments, conventional medical wisdom had maintained that the human body could probably survive no more than 17-18 instantaneous g.